From: Pavel Begunkov asml.silence@gmail.com
commit 43597aac1f87230cb565ab354d331682f13d3c7a upstream.
__io_rsrc_put_work() might need ->uring_lock, so nobody should wait for rsrc nodes holding the mutex. However, that's exactly what io_ring_ctx_free() does with io_wait_rsrc_data().
Split it into rsrc wait + dealloc, and move the first one out of the lock.
Cc: stable@vger.kernel.org Fixes: b60c8dce33895 ("io_uring: preparation for rsrc tagging") Signed-off-by: Pavel Begunkov asml.silence@gmail.com Link: https://lore.kernel.org/r/0130c5c2693468173ec1afab714e0885d2c9c363.162855978... Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/io_uring.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-)
--- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -8614,13 +8614,10 @@ static void io_req_caches_free(struct io mutex_unlock(&ctx->uring_lock); }
-static bool io_wait_rsrc_data(struct io_rsrc_data *data) +static void io_wait_rsrc_data(struct io_rsrc_data *data) { - if (!data) - return false; - if (!atomic_dec_and_test(&data->refs)) + if (data && !atomic_dec_and_test(&data->refs)) wait_for_completion(&data->done); - return true; }
static void io_ring_ctx_free(struct io_ring_ctx *ctx) @@ -8632,10 +8629,14 @@ static void io_ring_ctx_free(struct io_r ctx->mm_account = NULL; }
+ /* __io_rsrc_put_work() may need uring_lock to progress, wait w/o it */ + io_wait_rsrc_data(ctx->buf_data); + io_wait_rsrc_data(ctx->file_data); + mutex_lock(&ctx->uring_lock); - if (io_wait_rsrc_data(ctx->buf_data)) + if (ctx->buf_data) __io_sqe_buffers_unregister(ctx); - if (io_wait_rsrc_data(ctx->file_data)) + if (ctx->file_data) __io_sqe_files_unregister(ctx); if (ctx->rings) __io_cqring_overflow_flush(ctx, true);